In traditional usability testing, the moderator/observer would either sit beside the participant giving instructions, or sit in another room, giving instructions via a speaker system.
© Luca Mascaro
With an increasing number of users in the UK and similar countries seemingly permanently attached to their smart phone, it would be interesting to try an experiment where task instructions and prompts were given via SMS messages.
© Thomas Geiregger
The moderator would still be close by giving instructions, but instead of giving instructions via an audio system they could send the participant instructions via SMS. This would of course affect the time on task but may be less intrusive for the user compared to feeling that they are being observed by big brother.